The five elements; Fluorine (F), Chlorine (Cl), Bromine(Br), Iodine (I) and Astatine (At) belonging to VII A Group of the modern periodic table are collectively referred as halogens. The last element Astatine is radioactive and is very short lived hence generally excluded from the study. The word halogen is derived from the Greek words Halos […]
Category: Pure Sciences
Simple Machines: Levers
Science > Physics > Simple Machines > Levers A simple machine is a mechanical device that makes our life easier. If a force is applied at one point, the simple machine transmits it to another point with a convenient change of magnitude and direction. In this article we shall study the terminology associated with the […]
Refraction Through Prism
Science > Physics > Refraction of Light > Refraction Through Prism In this article, we shall study refraction through prism. Prism: A prism is a portion of a transparent medium which is bounded by non-parallel plane surfaces. The two plane surfaces ABCD and AEFD intersecting each other in line AD are called the refracting faces […]
Preparation of Colloids
Science > Chemistry > Colloids > Preparation of Colloids In this article, we shall study different methods of preparation of colloids. Preparation of Lyophilic Sols: For preparing lyophilic sol, the dispersed phase is directly added to dispersion medium in cold or by warming. Colloidal solutions of starch, glue, gelatin, etc. in water can be prepared […]
Associated Colloids (Micelles)
Science > Chemistry > Colloids > Associated Colloids (Micelles) In thisarticle, we shall study bout associated colloids :micelles). Multimolecular Colloids: Multimolecular colloids are those systems in which the dispersed phase particles are aggregates of many atoms or molecules. The particles in this colloidal solutions are held together by van der Wall’s forces. e.g. gold sol particles […]
Types of Colloidal Solutions
Science > Chemistry > Colloids >Types of Colloidal Solutions In this article, we shall study types of colloidal solutions (systems) on the basis of states of the dispersed phase and dispersion medium, the interaction between the dispersed phase and dispersion medium, and on the number of atoms and molecules in a colloidal particle. Types of […]
Introduction to Colloids
Science > Chemistry > Colloids > Colloidal Solutions Depending upon the size of particles in solution, solutions are classified as true solutions, colloidal solutions, and suspensions. In this article, we shall study colloids i.e. colloidal solutions. Historical Background: The foundation of colloidal chemistry was laid by English chemist Thomas Graham in 1861. Other prominent chemists […]
Applications of Adsorption
Science > Chemistry > Surface Chemistry > Applications of Adsorption In this article, we shall study some applications of adsorption. Adsorption Indicators: The phenomenon of adsorption is used to detect the endpoints of precipitation titrations. In such titrations, dyestuffs like eosin, fluorescein, alizarin red etc, are used as adsorption indicators. At the endpoint of the […]
Science > Chemistry > Surface Chemistry > Application of Adsorption: Catalysis In this article, we shall discuss very important application of the phenomenon of adsorption, called catalysis. Remaining applications are discussed in the next article. Catalyst: A catalyst is defined as a substance which when added to the reacting system increases the rate of the […]
Factors Affecting Adsorption
Science > Chemistry > Surface Chemistry > Factors Affecting Adsorption In last article, we have studied the meaning of terms like adsorption, absorption, adsorbate, adsorbent. In this article, we shall study the factors affecting adsorption. The Extent of Adsorption: The quantity of an adsorbate that is adsorbed per unit mass of adsorbent is called extent […]